HCNSO Student Theses and Dissertations

Defense Date

4-28-2020

Document Type

Thesis

Degree Name

M.S. Marine Biology

First Advisor

David Kerstetter, Ph.D

Second Advisor

J. Matthew Hoch, Ph.D

Third Advisor

Charles Messing, Ph.D

Abstract

The coastlines of Florida are becoming highly urbanized, and the growing human population is affecting many mangrove and estuarine habitats. Exploring the predation efficiency and prey choice of estuarine organisms under varying anthropogenic light types and intensities could help determine anthropogenic effects. Mangrove habitats support both relatively large predators such as Blue Striped Grunt (Haemulon sciurus) and Gray Snapper (Lutjanus griseus), and a diversity of smaller taxa that occupy lower trophic levels, including Grass Shrimp (Palaemonetes paludosus) and Mosquitofish (Gambusia holbrooki). Understanding how predation (or predation evasion) efficiencies are affected by different light intensities should offer guidance for managing South Florida coastal ecosystems subject to the effects of increased urbanization.

The goals were to determine if different artificial light intensities and types (1) affect predation efficiency, and (2) alter prey choice, for two mid-level predators found in the south Florida mangrove ecosystem. Under experimental conditions with LED, halogen, and incandescent sources, Mangrove Snappers and Blue Striped Grunts were exposed to combinations of prey. For predation efficiency, LED at its brightest level showed the highest decrease in predation efficiency of both predator species. For prey preference, the Grass Shrimp seemed to be the preferred prey over Mosquitofish under all light conditions for both predator species. Overall, light intensity and light type has some effect on nocturnal predation efficiency and prey choice. Humans influence affects aspects of the near shore ecosystems, and it is important to explore the extent of those effects on behaviors of species in estuarine habitats.

Available for download on Tuesday, June 08, 2021

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